Complete description of a quantum system at a given time
... generalized states provides a natural language for describing many peculiar situations. In particular, situations in which one can ascertain the result of a measurement of any one of several non-commuting variables are analysed. 'Weak measurements on quantum systems described by generalized states a ...
... generalized states provides a natural language for describing many peculiar situations. In particular, situations in which one can ascertain the result of a measurement of any one of several non-commuting variables are analysed. 'Weak measurements on quantum systems described by generalized states a ...
manuscript - University of Hertfordshire
... and added complexity of quantum phase space dynamics. At the same time it provides, through the conservation of the flow winding number !, the basis for an analysis of its topological invariants, ordering this complexity. Systems that have been studied using quantum phase space techniques can be ana ...
... and added complexity of quantum phase space dynamics. At the same time it provides, through the conservation of the flow winding number !, the basis for an analysis of its topological invariants, ordering this complexity. Systems that have been studied using quantum phase space techniques can be ana ...
Shannon entropy as a measure of uncertainty in positions and
... Entropic uncertainty relations for the position and momentum, or other canonically conjugated variables have been derived a long time ago. Initial investigations [1] were devoted to continuous Shannon entropies. Further generalizations took into account, in the spirit of Deutsch [2] and Maassen–Uffink ...
... Entropic uncertainty relations for the position and momentum, or other canonically conjugated variables have been derived a long time ago. Initial investigations [1] were devoted to continuous Shannon entropies. Further generalizations took into account, in the spirit of Deutsch [2] and Maassen–Uffink ...
Experimental Implementation of Adiabatic Passage between
... example is the Wen-plaquette model, which includes manybody interactions. Such interactions have not been found in naturally occurring systems, but they can be generated as effective interactions in quantum simulators. Using a NMR quantum simulator, we provide a first proof-of-principle experiment t ...
... example is the Wen-plaquette model, which includes manybody interactions. Such interactions have not been found in naturally occurring systems, but they can be generated as effective interactions in quantum simulators. Using a NMR quantum simulator, we provide a first proof-of-principle experiment t ...
Quantum error correction
... and communication in the presence of noise is error correction. Classical error correction is a well developed field with tested methods and codes. Quantum systems, especially when used in quantum computation rely on large scale interference which is fragile and needs a good protection against noise ...
... and communication in the presence of noise is error correction. Classical error correction is a well developed field with tested methods and codes. Quantum systems, especially when used in quantum computation rely on large scale interference which is fragile and needs a good protection against noise ...
Quantum Probability - Institut Camille Jordan
... Furthermore, their associated probability spaces have nothing to do together. They cannot be put together, as one usually does in the case of independent random variables, by taking the tensor product of the two spaces, because the two random variables X and Y are not independent. As operators on H ...
... Furthermore, their associated probability spaces have nothing to do together. They cannot be put together, as one usually does in the case of independent random variables, by taking the tensor product of the two spaces, because the two random variables X and Y are not independent. As operators on H ...
The Tenth Rochester Conferences on Coherence Quantum Information and Measurement
... and interesting wines together with OSA and ICO award presentations, as well as a talk by Paul Kelley, A century of Advances in Optics. We will also publish a volume highlighting the progress that has been made in the past six years in the fields of coherence and quantum optics as well as the beginn ...
... and interesting wines together with OSA and ICO award presentations, as well as a talk by Paul Kelley, A century of Advances in Optics. We will also publish a volume highlighting the progress that has been made in the past six years in the fields of coherence and quantum optics as well as the beginn ...
Quantum critical dynamics of the random transverse-field Ising spin chain
... chain in a transverse field [2]. Both models can be mapped onto a system of non-interacting fermions, where the equal-position correlation functions are calculated by the Pfaffian method utilizing the theory of Töplitz determinants. In this letter we consider —for the first time— the critical dynam ...
... chain in a transverse field [2]. Both models can be mapped onto a system of non-interacting fermions, where the equal-position correlation functions are calculated by the Pfaffian method utilizing the theory of Töplitz determinants. In this letter we consider —for the first time— the critical dynam ...
Why We Thought Linear Optics Sucks at Quantum Computing
... approach to the result. If the authors … bolster their evidence … the manuscript might be suitable for publication in Physical Review A. ...
... approach to the result. If the authors … bolster their evidence … the manuscript might be suitable for publication in Physical Review A. ...
Can one distinguish quantum trees from the boundary?
... matrix and Lax-Phillips scattering operator for the noncompact graph obtained by attaching semi-infinite wires to all boundary vertices. Hence this matrix function encodes all information that can be obtained by boundary measurements. Extending the spectral data set further by including TW-functions ...
... matrix and Lax-Phillips scattering operator for the noncompact graph obtained by attaching semi-infinite wires to all boundary vertices. Hence this matrix function encodes all information that can be obtained by boundary measurements. Extending the spectral data set further by including TW-functions ...
Do dispositions and propensities have a role in the
... • In favour of 1, Bohr might have added that the definiteness of properties of M is a necessary condition to attribute even a disposition to the entity before the measurement interaction. If M has no position, it has no property at all involving position, not even a dispositional one! ...
... • In favour of 1, Bohr might have added that the definiteness of properties of M is a necessary condition to attribute even a disposition to the entity before the measurement interaction. If M has no position, it has no property at all involving position, not even a dispositional one! ...
Quantum key distribution
Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the most well known example of the group of quantum cryptographic tasks.An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography which relies on the computational difficulty of certain mathematical functions, and cannot provide any indication of eavesdropping at any point in the communication process, or any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy.Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm. In the case of QKD this comparison is based on the assumption of perfect single-photon sources and detectors, that cannot be easily implemented.